13
Rapid Control of Arterial Rapid Control of Arterial Pressure by Nervous System Pressure by Nervous System By: By: M. Rasjad Indra M. Rasjad Indra Lab. Ilmu Faal FK Lab. Ilmu Faal FK UNIBRAW UNIBRAW

Pengendalian tekanan darah

Embed Size (px)

Citation preview

Page 1: Pengendalian tekanan darah

Rapid Control of Arterial Rapid Control of Arterial Pressure by Nervous Pressure by Nervous

SystemSystem

By:By:

M. Rasjad IndraM. Rasjad Indra

Lab. Ilmu Faal FK UNIBRAWLab. Ilmu Faal FK UNIBRAW

Page 2: Pengendalian tekanan darah

Pengendalian sirkulasi oleh sistem Pengendalian sirkulasi oleh sistem sarafsaraf

Peran sistem saraf dalam pengendalian Peran sistem saraf dalam pengendalian aliran darah lokal aliran darah lokal sangat kecil.sangat kecil.

Sistem saraf lebih berperan pada fungsi Sistem saraf lebih berperan pada fungsi global dalam hal:global dalam hal:

1.1. Pendistribusian darah ke area tubuh tertentuPendistribusian darah ke area tubuh tertentu

2.2. Kekuatan pompa jantungKekuatan pompa jantung

3.3. Pengendalian cepat tekanan darah Pengendalian cepat tekanan darah

Page 3: Pengendalian tekanan darah

Three Major Changes Three Major Changes

If sympathetic nervous system are stimulatedIf sympathetic nervous system are stimulated1.1. Almost all arterioles are constrictedAlmost all arterioles are constricted

• Increases the total peripheral resistanceIncreases the total peripheral resistance

2.2. The veins especially & other large vessels are The veins especially & other large vessels are strongly constrictedstrongly constricted• Increases venous return Increases venous return increase cardiac out put increase cardiac out put

(Starling Law)(Starling Law)

3.3. The heart enhancing cardiac pumpingThe heart enhancing cardiac pumping• Increases heart rateIncreases heart rate• Increases cardiac contractilityIncreases cardiac contractility

Page 4: Pengendalian tekanan darah

Anestesi spinal menyebabkan penurunan tekanan darah akibat hilangnya tonus vasomotor

Page 5: Pengendalian tekanan darah

Reflex Mechanism for Maintaining Reflex Mechanism for Maintaining Normal Arterial PressureNormal Arterial Pressure

Baroreceptor Reflexes:Baroreceptor Reflexes:– The receptors: Baroreceptors or PressoreceptorsThe receptors: Baroreceptors or Pressoreceptors

Located in the wall of several of large systemic Located in the wall of several of large systemic arteriesarteriesSinus caroticus Sinus caroticus n. Hering n. Hering n. Glossopharyngeus n. Glossopharyngeus tr. Solitarius tr. Solitarius Med. Oblongata.Med. Oblongata.Arcus aortae Arcus aortae n. Vagusn. Vagus

– The Response: Feedback signals to reduce The Response: Feedback signals to reduce arterial pressurearterial pressure

Vasodilatation of the veins and arteriolesVasodilatation of the veins and arteriolesDecreased heart rate & the strength of heart Decreased heart rate & the strength of heart contractioncontraction

Page 6: Pengendalian tekanan darah

Efek perubahan tekanan arteri (ΔP) terhadap perubahan transmisi impuls n. Hering dari sinus Caroticus (ΔI)

Baroreseptor lebih merespons perubahan tekanan daripada tekanan stasioner

Page 7: Pengendalian tekanan darah

Penjepitan a. carotis communis menyebabkan peningkatan tekanan arteri (MAP), pelepasan jepitan menurunkan tekanan arteri

Page 8: Pengendalian tekanan darah

Function of Baroreceptor ReflexFunction of Baroreceptor Reflex

During changes in Body PostureDuring changes in Body Posture– To maintain relatively constant arterial To maintain relatively constant arterial

pressure in the upper bodypressure in the upper body

Pressure BufferPressure Buffer Function Function– Opposes either Opposes either increasesincreases or or decreasesdecreases in in

arterial pressure.arterial pressure.

Unimportance of Baroreceptor System for Unimportance of Baroreceptor System for Long RegulationLong Regulation– The resetting of baroreceptor systemsThe resetting of baroreceptor systems

Page 9: Pengendalian tekanan darah

Pencatatan tekanan darah selama 2 jam pada kondisi NORMAL (gambar atas) dan pada beberapa minggu setelah DENERVASI sinus caroticus dan Sinus aorticus

Page 10: Pengendalian tekanan darah

Frekuensi distribusi MAP selama 24 jam pada anjing NORMAL dan beberapa minggu setelah denervasi baroreseptor

Page 11: Pengendalian tekanan darah

Chemoreceptors Reflex:Chemoreceptors Reflex:– The receptors sensitive to:The receptors sensitive to:

Lack of oxygens; COLack of oxygens; CO22 excess and H excess and H++ excess. excess.

Located in the wall of small arteries; Carotid Bodies & Aortic Located in the wall of small arteries; Carotid Bodies & Aortic Bodies.Bodies.

– Not a powerful control in a normal arterial pressure Not a powerful control in a normal arterial pressure rangerange

Important in below 80 mmHgImportant in below 80 mmHg

Low-pressure Receptors:Low-pressure Receptors:– Stretch receptorsStretch receptors– Located in the wall of: Pulmonary arteries & AtriumLocated in the wall of: Pulmonary arteries & Atrium– Role: to minimize arterial pressure changes in Role: to minimize arterial pressure changes in

response to changes in blood volume.response to changes in blood volume.

Reflex Mechanism for Maintaining Normal Reflex Mechanism for Maintaining Normal Arterial Pressure (Cont.)Arterial Pressure (Cont.)

Page 12: Pengendalian tekanan darah

Volume Reflex (Volume Reflex (Atrial Reflex that Activate the KidneyAtrial Reflex that Activate the Kidney))– Stimulation: Stretch of the atriaStimulation: Stretch of the atria– Response: Response:

1.1. Dilatation of the afferent arteriole in the kidneyDilatation of the afferent arteriole in the kidney

2.2. To Hypothalamus To Hypothalamus Decrease ADH secretion Decrease ADH secretion

3.3. Release of Atrial Natriuretic Peptide (ANP)Release of Atrial Natriuretic Peptide (ANP)

The Bainbridge ReflexThe Bainbridge Reflex– Stimulation: Stretch of the atriaStimulation: Stretch of the atria– Response: n. Vagus Response: n. Vagus Med. Oblongata Med. Oblongata Increase the Increase the

heart rate & strength of the heart contractionheart rate & strength of the heart contraction

Reflex Mechanism for Maintaining Reflex Mechanism for Maintaining Normal Arterial Pressure (Cont.)Normal Arterial Pressure (Cont.)

Page 13: Pengendalian tekanan darah

CA

CI

HIGHER CENTER

VASOMOTORCENTERCI CA

JANTUNG

SV Hr

C.O.PX

TPR

“Blood Pressure”O2

H

CO2

PH

CHEMORECEPTOR

+

VCVD

+

“Baroreceptor”

-

BARORESEPTORCONTROL “Blood Pressure”